Distance to be covered = 500 meters
Effective speed will be equal to difference in the speed of ma and train as they move in opposite directions.
Thus, effective speed = 63kmph-3kmph= 60kmph.
60kmph is equal to 50/3 m/s.
Time = Distance/ Speed
Thus, time taken will be equal to 500/(50/3).
On solving, time = 30 seconds.
Therefore, the train will take 30 seconds to overtake the man.